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COATING OR PLASTIC.

TATE'S PATEN" e OBERT SPENCER, on NEW roux, n.

" IMPROVED FIRE- PROOF COMPOUND.

ffspecification forming part of Letters Patent No. 84,143, datedNovember 17, 1868.

To all whom it may concern.-

Be it known that I, ROBERT SPENCER, of the city and county of New York,in the State of New York, have invented a new and Improved Fi reProofCompound and I do hereby declare that the following is a full, clear,and

' exact description thereof.

This invention has for its object theprodnction of a new and usefulcompound which will resist the action of very high degrees of heat, andwhich is adapted for use in the manufacture of crucibles, pyrometers,firebricks, retorts, and other objects; also, for coating or liningmolds in which castings are made, and for coating or lining otherobjects which are to be exposed to intense heat.

The improved compound consists of silicate of soda, or soluble glass,plumbago, and fireclay.

I take equal parts of ilumba o fire-cla and silicate of sgda, and mmtoge er y g'rint 111g. This forms a plastic compound, which can bemolded and )ressed into any desired form, ammm baking. v

' For the purpose of forming a fire-proof paint, which will protect thesurfaces of metallic and mineral substances from rapid destruction whenexposed to intense heat, I take,"sa-y, equal parts of plumbago andfire-clay, reduced to a fine powder, and mix with them a sufficientquantity of silicate of soda to make am n fluid, which can be applied tosurfaces with a brush.

While I prefer to use equal proportions of the substances above named inthe production of the molding compound, I do not confine myself to theseexact proportions, as they may tained.

. I am aware that. fire-bricks, and other 01);?

jects designed for exposure to intense heat,- have been made of avariety of refractory substances, such as ghtyg'asbestus, and soapstone;but it is found in pract'imhat such Te'fifictory substances do notcement'together well, and when subjected to a high degree of heat for along time they crumble and crack.

. To obviate this object-ion I use, in combination with plumbago andfire-clay, the silicate of soda, which I have found will cement the two,and form a solid refractory mass, that will not crumble when exposed tointense heat and the action of sulphurous fumes.

What I claim as new, and desire to secure by Letters Patent, is-

A fire-proof molding compound or paint, composed of the within-describedingredients, mixed together iuabout the proportions set forth. v

y ROBT. SPENCER.

Witnesses:

R. T. CAMPBELL, J. V. CAMPBELL.

